In an active matrix display device with light-emitting elements, variation in the threshold values of transistors (driver transistors) which are provided in respective pixels and control the values of currents supplied to the light-emitting elements in accordance with image signals is reflected on the luminance of the light-emitting elements. Patent Document 1 discloses a display device in which, in order to prevent variation in threshold values from affecting the luminance of light-emitting elements, characteristics of a driver transistor of each pixel are measured in advance and an image signal corrected on the basis of the measured characteristics is supplied to the pixel.
Specifically, the potentials of driver transistors of pixels in a given row are set to a specific value such that the transistors operate in a saturation region, and currents flowing through the individual driver transistors are measured. Such operation is sequentially performed on the driver transistors of the pixels in all rows.
Note that such a problem is common to not only display devices but all devices that include components (e.g., pixels) arranged in a matrix and perform processing such as display, measurement, detection, or arithmetic operation with a current flowing through one or more electrical elements (e.g., transistors) existing in each component.